Java圖片透明-很有意思

先聲明一下，以下的代碼不是我本人寫的，我只是在這個基礎上小修了一把：
package com.dlh;

import java.awt.Graphics;
import java.awt.Image;
import java.awt.MediaTracker;
import java.awt.Point;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.Toolkit;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseMotionAdapter;
import java.awt.geom.Area;
import java.awt.image.PixelGrabber;
import java.io.File;
import java.io.IOException;
import java.util.ArrayList;

import javax.swing.JFrame;

//import com.sun.awt.AWTUtilities;
import com.sun.jna.platform.*;
import com.sun.jna.win32.*;


public class IrregularFormSample extends JFrame {

private static final long serialVersionUID = 1L;
private Point origin;
private Image img;

public IrregularFormSample() {
super();
MediaTracker mt=new MediaTracker(this); //dog.png,Image0.jpg
img=Toolkit.getDefaultToolkit().createImage("image//dog.png");
mt.addImage(img, 0);
try {
mt.waitForAll();
} catch (InterruptedException e) {
e.printStackTrace();
}

try {
initialize();
} catch (IOException e) {
e.printStackTrace();
}
}


private void initialize() throws IOException {
this.setSize(img.getWidth(null), img.getHeight(null));
this.setUndecorated(true);
this.origin=new Point();


WindowUtils.setWindowMask(this, getImageShape(img));
//AWTUtilities.setWindowShape (this, getImageShape(img));
//AWTUtilities.setWindowOpacity(this, 0.8f);

this.setLocationRelativeTo(null);
addMouseListener(
new MouseAdapter(){
public void mousePressed(MouseEvent e){
origin.x = e.getX();
origin.y = e.getY();
}

public void mouseClicked(MouseEvent e) {
if(e.getButton()==MouseEvent.BUTTON3)
System.exit(0);
}
public void mouseReleased(MouseEvent e) {
super.mouseReleased(e);
}
@Override
public void mouseEntered(MouseEvent e) {
repaint();
}
}
);

addMouseMotionListener(
new MouseMotionAdapter(){
public void mouseDragged(MouseEvent e){
Point p = getLocation();
setLocation(p.x + e.getX() - origin.x, p.y + e.getY() - origin.y );
}
}
);
}



public Shape getImageShape(Image img) {
ArrayList<Integer> x=new ArrayList<Integer>();
ArrayList<Integer> y=new ArrayList<Integer>();
int width=img.getWidth(null);
int height=img.getHeight(null);


PixelGrabber pgr = new PixelGrabber(img, 0, 0, -1, -1, true);
try {
pgr.grabPixels();
} catch (InterruptedException ex) {
ex.getStackTrace();
}
int pixels[] = (int[]) pgr.getPixels();


for (int i = 0; i < pixels.length; i++) {

int alpha = getAlpha(pixels[i]);
if (alpha == 0){
continue;
}else{
x.add(i%width>0 ? i%width-1:0);
y.add(i%width==0 ? (i==0 ? 0:i/width-1):i/width);
}
}


int[][] matrix=new int[height][width];
for(int i=0;i<height;i++){
for(int j=0;j<width;j++){
matrix[i][j]=0;
}
}


for(int c=0;c<x.size();c++){
matrix[y.get(c)][x.get(c)]=1;
}


Area rec=new Area();
int temp=0;

for(int i=0;i<height;i++){
for(int j=0;j<width;j++){
if(matrix[i][j]==1){
if(temp==0)
temp=j;
else if(j==width){
if(temp==0){
Rectangle rectemp=new Rectangle(j,i,1,1);
rec.add(new Area(rectemp));
}else{
Rectangle rectemp=new Rectangle(temp,i,j-temp,1);
rec.add(new Area(rectemp));
temp=0;
}
}
}else{
if(temp!=0){
Rectangle rectemp=new Rectangle(temp,i,j-temp,1);
rec.add(new Area(rectemp));
temp=0;
}
}
}
temp=0;
}
return rec;
}


private int getAlpha(int pixel) {
return (pixel >> 24) & 0xff;
}



@Override
public void paint(Graphics g) {
super.paint(g);
g.drawImage(img, 0, 0, null);
}

public static void main(String[] args) {
IrregularFormSample sample = new IrregularFormSample();
sample.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
sample.setVisible(true);
}
}

要引入附件兩個包，這個就可以跨平臺了（我也只是聽說，你可以驗證一下)，如果用jdk中com.sun.awt.AWTUtilities，在linux下是不行的。

看一下，這個狗有趣吧

[img]http://dl2.iteye.com/upload/attachment/0102/8392/9e5b6909-d8aa-322a-a1c4-777c1f6d7c76.png[/img]